Also referred to as Mac-in-Mac, the provider backbone bridge (PBB) technology is defined by the IEEE 802. 1ah draft standard, and achieves complete separation of the user network from the provider network by packaging user media access control (MAC) to the common network MAC for transmission.
In order to solve the problem of network expansibility, PBB can be used by combining with the technology of hierarchical virtual private local area network services (H-VPLS). By forwarding virtue of PBB+H-VPLS, it suffices for the user facing provider edge (UPE) to acquire the MAC addresses of local users and users at the opposite end and the MAC address of the common network in the virtual switch instance (VSI), and it suffices for the network provider edge (NPE) to acquire the MAC address of the common network in the VSI, thereby greatly reducing the number of MAC tables of the network provider edge NPE, so that expansion of network specifications is no longer restricted.
In the PBB H-VPLS network, deployed on the user facing provider edge UPE can be a backbone component (B-Component) that provides bridging function based on backbone MAC (B-MAC) address and backbone tag (B-TAG) information. A service instance component (I-Component) that provides bridging function based on user MAC address and source virtual local area network (S-LAN) information can also be deployed on the B-Component.
Currently, in order to achieve the objective of sharing load in the PBB H-VPLS network, the UPE is configured with different backbone source MACs (B-SMACs) under the service I-Component, and the NPE performs Hash routing based on the service I-Component through the different B-SMACs.
However, as the inventor found during the process of implementing the present invention, the prior art technology is defective in the fact that, since each B-Component can have great quantities of service I-Components, the UPE should be equipped with a mass of B-SMACs, and the NPE should also create a mass of forwarding tables, thus bringing undue load to the edging device.